Carburetor



met. 25,1923.

G. C. FARRIS CARBURETOR Filed June 22 1921 2 Sheets$heet l G. C. FARRIS CARBURETOR Filed June 2,2, 1921 2 Sheets-Sheet; 2

wuewto q Grower eC'fk/w GBOVEE G. FARR-I257, @WFTJBSEGLIQ, VIRGINIA, ASSIGNOR T GLIFTUN OGEi-lll' VIEW, VIEGZXHQ n rlrionr soie or oncnnron.

.ipplicetion filed June 22, 1821. Serial No. 279,683.

To all whom may concern.

Be it known that I, Gnovnn C. FARMS, e citizen of the .-;United States, residin at Norfolk, in the county of Norfolk and btate e of Virginia have invented new and useful 1m rovements in Gsrburetors, of which the fol owing is a specification.

This invention relates to carburetors and more particulcrl to that class of carbu- EIZB rotors in which tie richness of the combustible mixture is controlled by c sliding venturi shifteble with respect to the mouth oi the main fuel nozzle.

One of the objects of this invention is to w v produce a. carburetor which is characterized by a construction in which there is no auxiliary admission of air at high speeds of the motor with which said carburetor is'used, and in which the entire air supply comes in till by c main channel the excess richness of mixture incident to the absence of air being corrected not only by c shi'itsble venturi such as is usual in some carburetors, but by means of cutting old the idling jet more, or

3% less or entirely, at high speeds of the motor.

Another object of the'invention is to pr0- vide throttle operated means for cutting off the idling jet when the throttle is opened to s predetermined extent.

95? ,A further object of the invention is to so associate the venturi and; idling jet closing means that both are operated by the opening of the throttle. I Still. another object of the invention is to so flexibly connect the throttle to the venturi so that sudden opening of the throttle will be accompanied by gradual rising of the venturi so as to prevent starvation of the engine due to sudden falling in co air past the main fuel jet.

j Another object of the invention is to pro vide a flexible connection between the throttle and venturi and means to hold the venturi in depressed position against the openfi ing movement of the throttle for the purpose of priming.

With the above and other objects in View, my invention consists in the improved can buretors illustrated in the accompanying t drawings, described in the following speci fieetion, and particularly claimed, and -in such variations and modifications thereof as will be obvious to those skilled in the art to which my invention relates.

w In the drawings eccoznoenying end formthe velocity of the ing a part of this specification, and wherein the preferred embodiment of my invention is illustreted:

Figure 1 is a, vertical section of my i provedv carburetor with the throttle closed. or Figure 2 is a similar view of the upper" portion or" the carburetor showing the throttle open.

Figure 3 is a vertical section of the upper portion of the carburetor shown in igure 1 viewed from the left.

Figure 4- is a, horizontal section taken along the line 66 of Figure 1.

, Fl ure 5 is at similarview taken on the line of F i re 1. y

' In the drawings the main casting 1 or the carburetor is provided with en an inlet chamber 2 end an upright cylindrical mixing chamber 3 in communication therewith. The wall of said mixing chamber is bored out at 4. to form on idling Well having s narrow assage-Way 5 extending longitudiholly oi the Well of said mixing chember and communicating therewith et a point-5e adjacent the edge of the throttle valve 6 when the latter is in closed position forming on idling nozzle 54 controlled by the needle valve 55. The casting l is with sfloat'chamloer 8 which communicates by n horizontal bore 9 with the idling well and with the main fuel nozzle 10 which opens into the mixing chamber 3 through a. narrow orifice 11. The costing l is bored out at 12 forming a socket which is threaded for the reception of at liquid fuel supply 96 pipe not shown. Said bore 1211s in communication with a. sediment chamber 13 into which opens the passage 1% controlled by the float valve 15.

To the float valve issecured a metallic float 16 determining the level of liquid fuel in said float chamber. The float is con-f trolled by the usual weighted levers 17 which are pivoted at 18 to depending lugs 19 forming part of the cover 20 of the float chamber.

The bottom of the sediment chamber 13 is closed by a plug 21, by the removal of which the sediment may be drained. The plug 22 which carries the seat 23 of the float valve and the passage lee-ding ihereto. is also re .moveble-by Withdrawing it through. the

opening occupied by the nut 24 upon remormg the latter. The main fuel nozzle ii is screwed to the also provided ice Nil

upper wall of the treneveree pessege 9 and is insertuhle from underside of said passage through an aperture closed by the plug Another aperture in the loiver Wall of the 9 and closed by a plug 26 is in alignment with the idling Well l. Upon removal of the plugs :25 and; 26 access is obtained both. to the idling well and; main fuel nozzle the w 1 These plugs are conveniently reached oy taking oil the removable bottom portion 52? of the air inlet chamber which is (letecheoly secured to the casting l by the thumonuts passing through epertured lugs 29 and 39 integral with said casting l and member 24 respectively.

The choke valve 31 is pivotelly mounted in the end of the air inlet passage 2 is operated by e bell crank 32 from the outsicle of the casting. The bushing 33 of the resin nozzle which carries the orifice ll is detachably secured to said main-fuel nozzle and; may be exchanged. for e bushing having en orifice of diilerent size according to the requirements of the motor with which the carburetor is intended to he used.

Slidebly arranged within the mixing chamber 3 in operative relation to the main fuel nozzle 11 is venturi 34% proviolecl externally with grooves and so in its upper and lower ends carrying pecking rings Whose function it is to seal the space between the walls of the venturi end mixing chamber. The function of the sliding venturi is to change the cross sectional area of the possage around the main fuel nozzle enzl so to vary the proportions of the combustible mixture.

The venturi 39%- is directly connected to the throttle operating mechanism by e pair of spiral springs 37 secured to pins .38 which project. from the venturi intermediate its ends at diametrically opposite points through slots 51 in the well of the mixing chamber. These slots lie between the piston rings throughout the range of movement of the latter and are thus sealed against communication with the interior of the mixing chamber. The other ends of said springs are made fast externally of the mixing chamher to ends of crank arms fixed to the op posite ends of the shaft 39 on which the throttle valve 6 is mounted. A. lever l0 fixed to one end of the shaft 39 leads to H1211) ual operating means not shown. By virtue of the resilient connection 37 between the venturi and the throttle valve operating mechanism a sudden opening of the throttle valve will result in a gradual elevation of the venturi due to the inertia of the venturi. end the strengthof the spring 37 being of such relative value to the Iweight of the venturi as to obtain this eil'ect.

positive depression of the. venturi even when the throttle valve 1S open, for the purpose of carburetorenriching the mixture for curring cable over pulley l5 extending to a: manual control not shown. By pulling on the cable 44: the enrls of the yoke Will bear against the pins of the venturi d pressing the letter against the tension of the spring 3? regardless of the position of the throttle.

The pulley is secured in e lug 46 made integral with the outer wall of the mixing chamber end. e shock absorbing s ring l? issttechecl to serial lug and to the gene to main tain the ends of seid yoke in. resilient contact at all times with she pin 38.

The iongii'iuclinu l flanges ere joineil by transverse flanges ll forming e frame on each side of the mixing chsxrher which cooperates with e removehle loor l5 pr ruling an enclosure in which the eetueting means for the venturi ere meinteinecl proiectctl from dust.

it is usual in carburetors for the iolling nozzle to open into "the mining chamber at a, point near the eclge of the throttle vslve when the latter is in closed position for the reason that when. the throttle valve is closed the passage between seicl valve and the Wall oi the mixing cherub-er is restrioteol so that the suction is concentrated at the idling nozzle. As the throttle valve is opened to increase the area oi the air passage between said valve and the Well of the mixing chemuer, the suction diminishes, end a smaller quantity of fuel is drawn through. the idling nozzle.

In at wide open position of the throttle valve there will ofoourse he the least, suction on the idling nozzle, but there is 'alweys some suction, and therefore an over richness of mixture this extent.

instead of resorting to the expedient of admitting auxiliary air to the mixture conduit between the carburetor and engine, the present invention ohvizites henecessitv for auxiliary air by the provision of a lip 52 attached to the venturi, which acts as a slide valve closing the idling nozzle 55 When the venturi is elevated. Being fixed in its relationto the venturi the idling nozzle closing means pertekes of all the flexibility of movetheventuri itself is capable, heing auto? merit relative to the throttle valve of which The resilient connection 37 also permits rnaticelly move l toclosing position when the throttle velve is openetl ens deemeed nuance along with the venturi to enrich the mixture by operation of the manual means 44:. I

While I have. above described what 1 have found to be a very practical embodiment of my invention, it is nevertheless to be understood that the carburetor may also be exemplified in numerous other alternative constructions and I accordingly reserve the right of adopting all such legitimate changes as may be fairly embodied within the spirit and scope of the invention as claimed.

Having described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a carburetor, a mixing chamber, a throttle valve therefor, a main fuel nozzle opening. into said chamber, an idling fuel nozzle in communication with said chamber, means for closing said idling nozzle, means resiliently connecting said throttle with said idling nozzle closing means, arranged to move the latter to closing position when the throttle is opened.

2. Ina carburetor, a mixing chamber, an air passage leading thereto, a. main fuel nozzle opening into said passage, an idling nozzle in communication with. the 'mixing chamber, a throttle valve, means for varying the ross sectional area of said air passage adjacent the main fuel nozzle, a valve for said idling nozzle carried by sald means and means for resiliently connecting said throttle valve and said area varying means.

3. In a carburetor, a mixing chamber, having an air passage leading thereto, a venturi slidable a main fuel nozzle I opening into said air passage, said mixing chamber being slotted adnected to said 7 yoke pivotal'ly mounted in the resiliently lifting in said mixing chamber,

jacent said ventuti, pins secured to said venturi and (passing through the slotted portions of sai mixing chamber, means conpins for lifting said venturi, a

mixing chamber,

and hearing at its ends on said pins of said venturi, means for said venturi, means connected to said yoke tending to move said vent-um resiliently in a direction in opposition to the pull of said lifting means, said venturi being movable in said last nalmed direction independently of said yo re.

4. In a carburetor, a mixing chamber, an air assage leading thereto, a main fuel nozze opening into said air passage, an idling nozzle in communication with the mixing chamber, a venturi in said mixing chamber for varyingthe cross sectional area of said air passage adjacent the main fuel nozzle, a va ve for said idling nozzle carried by said in spaced relation on said venturl engaging the Wall of said mixing chamber, said wall being provided with a slotted opening intermediate the paths of travel of" said sealing rings, operating-means for said venturi projecting thronghlsaid slotted openings, at throttle valve, and .means for resiliently connecting said throttle valve-and operating means.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

, GROVER C. FARRIS.

Witnesses:

MARION H. PIENEELSON, ALFRED ANDERSON.

wall of said venturi, sealing rings mounted 

